Dynamo-electric clutch.



W. MORRISON. DYNAMO ELECTRIC OLUTO15I.

APPLICATION FILED APR. 30, 1914. I

] Patented Jan. 26, 1915.

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W. MORRISON.

DYNAMO ELECTRIC CLUTCH.

APPLICATION FILED APR.30, 1914.

Patented Jan. 26, 1915.

3 SHEETS-SHEET 2.

W. MORRISON.

DYNAMO ELECTRIC CLUTCH.-

APPLICATION FILED APR.30, 1914.

Patented 72111.26, 1915-.

3 SHEETSSHEET 3.

wwmk/aow v W- M MOIBBZSON, 0F DES MOINES, IOWA.

DYNAMIC-ELECTRIC CLUTOH.

Specification of Letters Patent.

REISSUED Batented Jan. 26, 1915.

0 1 1 1 u m fl1ed .S eptg; nber;18, 1,913; Serial Ito-190,538. Divided and this application filed April 3o,. 1814'. serial No, 85,62.

Taallwlwm it may concern Be-it known that 1, WILL AM Monniso v, a citizen of the United States, residing at Des Moines, inthecolmty. of Polk and State of Iowa, haveinvented certain, new. and useful Improvements in Dynamo-Elcctrrc Clutches, of whichthefollowing; is a specification.

.My invention. relates to a power-transmission system, .capable of general application, but principally. designed and applied to automobiles driven by variable speed. gas-engines, in which system the power is transmitted from the gas-engine to the driven shaft through a dynamo-electric machine acting. as, a clutch, in such manner that but a small fraction of the power developed bvthe gas-engine is utilined in the clutch, the balance of the power being transmitted directly through the driven shaft.

My invention further provides. a system in which .the speed regulation ofthe auto- I mobile is effected, as in any ordinary gasenginedriven automobile, by varying the speed of the engine, the dynamo acting in the,..main supply as ;an electromagnetic clutch, and generating only enough current, under normal running conditions, to produce the requisite clutching effect. The requisite clutching efiect is that which will couple the engine shaft to the driven shaft by a magnetic pull sufiicient to enable the operationof the automobile under all normal speed conditions and under ordinary road conditions, but is not so great as to prevent a small speed variation between the driving anddriven shafts under abnormal conditions. Thus the clutch has under normal running conditions allthe effectiveness of a mechanical clutch, but is none the less capable of yielding to limited degree when there are sudden increases in. the load, such as occur momentarily during the starting and changing speeds or when the automobile strikes an obstacle or is otherwise suddenly. retarded. The elements of my new dynamo-electric clutch are therefore designed to produce this requisite clutching effect, the current, necessary to magnetize the rotary field magnet and rotary armature to, the extent required being generated at the outset in the armature at a comparati'vely very, small numberof slip revolu- .tio,ns,j .the' energy thus consumed ,in the etc. it is highly desirable that during the opclutch being, therefore, but a very small "fraction of that developed by the gas-engine, allthe remainin energydeveloped by the engine at speeds a ove that required for generating the clutching current being availableior load-driving purposes.

My invention further relates to the combination with a dynamo-electric clutch of this kind, of a storage battery Whose current is utilized for operating the dynamo erating incandescent lamps, sparking-coils, For reasons wh ch Will later appear,

lamps used for lighting, and maybe, for

example, from 2 to 8 volts. The armature of the dynamo 1s therefore wound with a large number of, turns and in such manner that, with asmall number of slip revolutions, it will generate current at a voltage substantially equal to that of the fully charged batteries when connected in the predetermined multiple relation. The field coils are so woundthat at the voltage described. there will be provided a suflicient numberIof ampere-turns to sufficiently mag- .netize the cores and provide a powerful magnetic field, the size of wire on both armatureand field being'properly proportioned to. safelycarry the current. In prac tice it has been found best to use a multipolar dynamo-electric machine, both eightpole and twelve-pole machines having been constructed and found to be efficient.

The invention of this application partic ularly relates to an improvement on or addition to the power-transmission system of my prior application SenNo. 784,458, filed August 12, 1913, and has for its object to utilize the centrifugal force produced by the rapid rotation of the rotors to assist to the desired extent the electromag.

. .as'a motor to start the gas-engine, for opnetic clutching action, either by so arranging the brushes and their cooperating moving parts, that the centrifugal force causes them to press against the commutator, or byprovidingthe rotors with interacting centrifugally-e erated sliding-clutch vdevices, indepen ent of thecurrent-collecting mechanism.

The construction and operation of a system embodying the invention will be 'apparent from the accompanying specifiers-- vention as applied to an automobile; i

7 and 8 show the relative positions of t e controller drums; Fi 9 is a vertical section through a, modi ed form of dynamoeleetric clutch having a se arate centrifugally-operated sliding clutc and Fig. 10 is an elevation of Fig. 9.

Referring to Fig. 1, A is the engine shaft and B the driven shaft, connected as shown in Fig. 6, through the usual speed-changing gears 80, to the driving ear of the automobile. Secured to the sha t A is the openended drum C, which may be of cast steel, having secured to its inner face the field magnet poles D, eight in number being indicated although any other suitable number may be used. Securedto or forming part of the shaft A is a stub-shaft E, on which is mounted, in ball-bearings, the armature F. To the flange G on the armature hub is secured, by any suitable means, the end of the automobile driving shaft B. For convenience of illustration, the armature has been shown with G'ramme-ring windings H, though I may use a drum armature with the coils wound in slots of a laminated "l he commutator rin J is carried on a series of arms K boltef armature. The commutator bars L are clamped into the ring and insulated therefrom in any desired manner. Each bar L has an inwardly projecting lug M to which the wires from the armature coils are connected. This commutator, it will benoted, has its brush-bearin surface on the inside, instead of the outslde. This is advantageoiis, since the brushes carried on the rotatmg field-drum are forced outwardly by the centrifugal force and thereby heldin firm contact withthe commutator bars.

The brushes are carried on two rings, N and O, bolted to the inner ends of the arms P secured to the drum 0. These rings are insulated from the arms P and from each other, and each carries, in the particular machine shown, a series of four brushes As shown in Fig. 2, the brushes Q, R are ig. 2 is a view.

to the body of the arms S, T against the inner face of the commutator The arms S, T are pivotall mounted on the brush-carrying rings 0, N and each of these arms has secured to or formed as a part of it, a notched ring 20. Around the pivot of each arm is wound a wire sprin with one end 21' seated in one of the note es in the ring 20, .and the other end 22 held in a clip or lug 23 secured to the carrying ring. it will be evident that by locating the end 21 of the sprin in one or the other of the notches that t 0 pressure of the springson arms S, T on the brushes can be increased or diminished.

The centrifugal force due to rotation tends. to throw the arms S, '1 and the brushes Q, R outward and the brushes are therefore forced more strongly than by the force of the springs alone, against the inside of the commutator, the increased friction tending to keep the two rotors in closer clutching relation, or, in other words, to diminish the sli The brushes, which may be of carbon, slide readily over the commutater, but as there are a number of these brushes, for example eight when the dynamo is an eight-pole machine, the pressure and ference of speed or sip between the ro-' tors may be additionally controlled in the manner hereinafter described.

Wires V and W conduct current from the brushes to the terminals V and W mounted on their respective rings, each ring, in this particular case, carrying four brushes.

These brush-carrying rings are connected to the proper collecting rings (to be referred to later) on the back of the drum (1.

The right-hand end of the drum is closed by a removable cover U, preferably madlin two parts so as to be readily disengaged. Mounted on the back or closed end of the drum is a series of collector rings 1, 2,

3, 4, insulated from the drum by a layer 5 of insulating material. A series of brushes 6, 7, 8, 9 (only one being fully illustrated) is supported on a fixed part 10 of theframc of the automobile. From the brushes 6, 7. 8, 9, wires 11, 12, 13, 14 lead to two separately operated controllers 90, 91, the connections bein diagrammatically shown in Fig. 3. 'lhe ack end of the drum is covered by a-casing (not shown).

90 is the engine-starting controller and 9.! that used in'the running position or that in which the dynamo -is used as a clutch.

As shown, the field coils F to F are connected in a series-multiple arrangement,

cells in series. 'Obviously, this particular number of units may be varied as varying conditions may demand.

The controller 91 consists of a drum of insulating material on the surface of which are arranged a number of longitudinal sets of separated contact blocks 7, f, As shown in Fig. 8, siX sets may be used. Located to engage these contact blocks are a series of brushes p, 72 connected, as shown, to the positive and negative ends of the battery units, and a second set of brushes e, e e c are connected to the conductors 11, 12, 13, 142. The blocks f of each set are electrically connected, as shown in dotted lines, and the blocks 7 are similarly connected. As shown in Fig. 3, the circuits are closed to establish the relations shown in Fig. 5.

The connections may be traced (Fig. 3) as follows :from armature brush 1) to junction 1, coils F F F F to junction 2, wire 12, brush 6 and its block f through the controller connection to a lower block 7, brush 6 wire 14:, junction 4:, the armature brush b At the same time, a circuit has been closed from junction 1, wire 11, brush 6 and a block 7", through controllerconnections to a lower block f, brush 6 wire 13, junction 3, coils F F and F F to junction 1. The battery units are also connected in multiple, and in shunt to the armature, their positive ends being connected together, through brushes p, blocks 7 and controller connections, wire 11, junction 1 and brush 7), while their negative ends are similarly, through brushes 72 blocks f and controller connections, connected together and to wire 14, junction 4 and brush 71 The arrangement of circuits thus produced is diagrammatically shown in Fig. 5.

The particular arrangement of circuitcontrollers described is not essential to my invention, as any other form by which the circuits may be connected in the manner described, may be used.

The controller 90 consists of a drum of insulating material on the surface of which is arranged a number of longitudinal sets of separated contact blocks 2. As shown in Fig. 7 six sets may be used. Located to engage these contact blocks is a series of brushes a, connected to the positive and negative ends of the battery units; and another set of brushes m is connected to the conductors 12 and 13. The blocks c 0 are each wide enough to engage the brushes m m, or n, a. As shown in Figs. 3 and 7,

the engine-starting circuits are all open,

none of the brushes being in engagement w th the contact blocks. If, however, the drum is rotated one step, the brushes will rest on contact blocks and circuits will be closed to connect the batteries in series relation and the field coils in series relation. The arrangement of circuits thus produced is diagrammatically shown in Fig. 4, with the field coils connected in a series relation, and all the battery units in series. So connected, the battery is delivering current to the armature of the dynamo to operate it as an engine-starting motor, while in the arrangement shown in Figs. 3 and 5, the paralleled batteries are connected to the armature to oppose the flow of current therefrom.

It will be noted that the batteries and field coils are arranged in shunt to the armature, so that whether the dynamo-electric machine is acting as a generator or a motor, the direction of rotation of the rotating field is the-same.

The controller drums may be operated by an escapement controller mechanism. which is described in an application, Serial No. 742,277, filed January 15, 1913. It will be sufiicient for the purposes of this application to state that by downward pressure of the foot the controller-drum is rotated one step to close its circuits, and upon release of the pressure, is given an additional step to open its circuits. The controllers may, of course, be operated by hand, or by any suitable mechanism.

As shown in Fig. 6, the controllers 90, 91 are operated by the foot-pedals 100, 101. pivoted on the frame of the machine and having connecting rods 102, 103. Retracting springs 10% and 105 are attached to the pedals in any suitable manner. Figs. 7 and 8 show the respective positions of the controller drums, one with circuits open when the circuits of the other are closed.

The operationof the system is as follows :The engine is started by causing the controller 90 to connect the field circuits across the middle block 0 and, at the same time, the battery is coupled in series by the wires leading to the brushes n, 22 as above described. The maximum voltage of the battery is therefore delivering current to the system, coupled as shown in Fig. i. the dynamo-electric machine acting as a shuntwound motor. As the automobile is at rest. preferably with the brakes applied, the armature connected to its driving shaft is held against rotation and the field-magnet rapidly rotates. The engine shaft is thereby also rotated and the engine started. The controller 90 is then rotated another step to break the connections above described. With the engine running, the brakes are released and the controller 91 is operated to-bring the system intothe condition shown in Fig. 5. As the field drum is now rotated by the engine, the dynamo-electric machine begins to act as a generator. .As soon as the sli between the rotors is large enough, the reqm-v driving the automobile. The automobile is steamor then operated in the usual way, the speed being controlled by throttling the engme, advancing or retarding the spark, or chan ing the gears,'as may be desired. As wil appear from Fig. 6, the dynamo element at-. tached to' the engine-shaft acts as the flywheel of the engine.

200 is the engine, which may be either a 4 to the engine.

' voltage at the brushes Under normal running conditions, the of the dynamo-clutch is equal tothat ofthe fully-charged battery, so that no current is delivered to the battery, all the current generated 'in the armature flowing over the field circuit. If, however, for any reason, such as consumption of current in startin the engine, l1ghting,- etc., the voltage of the battery is below the maximum, then part of the current generated by the slip will flow into and charge the battery, until the cells are again fully charged. For example, assuming that six-volt lamps are used, the battery 18 arran ed with sets of three cells in series, the sets eing in multiple. When fully charged, the voltage at the terminals of each set is approximately 71} volts, and as the dynamo is arranged to normally deliver current at this voltage, no current can flow into the battery, except upon the slight rise of voltage such as that due to a sudden pull. If, however, the cells are not fully charged, the voltage of the set might be, say, 6 volts, and current would flow into the batteries, being delivered, however, into all the paralleled sets of cells, so that the charging is effected at a relatively slow rate, which is highly desirable, the life of the cells would be lessened. The use of a plurality of cells or sets of cells is, therefore, of advantage in two respects, viz., that suflicient voltage is provided, when the battery is arranged in series relation, to furnish a powerful engine-starting current, and that, when connected in multiple releas-en 'ine, and 201 is a throttle for control ing tie-supply of motivefluld.

this charging currentas if charged too rapidly tion, they are cha rg'ed under the best contions.

In order that as little as possible of the a therefore capable of application to automobiles as now built,' where there is no room for extra motor and generating sets, since a generator sufiicient to produce the clutching-efl'ect is small in size. Moreover, a smaller gas-engine can be used to drive the car than would be necessary if the whole power developed by the gas-engine were converted into electrical energy to be used for running the car, since by my invention onl enough electrical energ is generated and used to produce the clutc ing-cflect, the

balance of the power of the gas-engine being transmitted, preferably through gears, to the driving shaft of the automobile.

In order properly to'design the clutch for a given machine, as for example an automobile, it is necessary first to measure, ex erimentally, the electrical energy require for clutching expressed in watts. at which this required power is to be generated isthen determined, the essential consideration being that it-should be as low as practicable, consistent with the character of the lighting-system. The dynamo is then designed in accordance with the well-known principles to develop the required power at the determined voltage, with due regard to the provision of a practically saturated field. Thearmature of such a machine is wound with as many turns as practicable of wire of the proper current-carrying. size, so that the necessary E. M. F. may be generated with the, fewest practicable number of slip-revolutions; the field being as'strong as practicable, or fully saturated. The field is wound "with a suliicient length and size of wire to take, if necessary, the entire quan tity of current generated by the armature to produce the required powerful clutchingeffect; and the field coils are wound with such resistances as, when in shunt with the batteries, to take their requiredamount of current, so that the fields and batteries will each get their proper proportion. The cells of the battery are, in the running position, arranged in parallel, in shunt with the fields, and this parallel arrangement is preferably the very lowest possible, a. e., with all the cells in parallel, as the slip needed to generate a .v0 tage suflicient to overcome the two and one-half volts E. M. F. of one lead storage cell, will then be reduced to the very The voltage necessary to Wind the armature for a higher voltage, say, that of two or three cells in series when lamps requiring a higher voltage are used, so that these lamps can be used while the machine is in operation; but the smallest parallel is much preferred, since the energy consumed in clutching is much less, as the relative difference of speed between the rotors may be less, and fewer revolutions of the engine are required to overcome the resistance of the low voltage cells. This method of connecting the cells in parallel is of further advantage in that when starting the automobile from rest with the engine still running, there is for a few seconds a larger quantity of current flowing from the electric clutch, and the batteries thus connected can take this excess current without danger of injury. I have manufactured these clutching generators of the shunt, compound, and 'series types, but the shunt machine has the great advantage that there is nodanger of reversal of the batteries, and no complicated regulating devices are required, which are hard to .avoid in series machines. Moreover, in the shunt machine it is not necessary to generate the extra voltage to overcome the resistance of the battery and the resistance of the field in series, as is the case with the compound or series machine, and the two moving parts can run in much closer clutching relation and with much greater efliciency. 4

Since the fields are shunt wound and in fixed vshunt relation with the armature and battery, and the armature runs in vthe same direction as a dynamo or motor, it permits the battery to drop in and act as a brake whenever the slip drops below the generating point, acting justas it does when starting the engine.

If while the automobile is running the batteries are thrown in, in series, as in the engine-starting position, instead of in parallel, as in the running position, a greater brakingefi'ect is produced, as under these conditions, the battery tends to run the car backward and the-engine forward, .the clutch itself thusacting as an emergency brake.

In the operation of an automobile provided with the dynamoelectric clutch ,above described, there are thus four forces tending to effect the relative-rate of revolution of the rotors, to wit :(1) the drag of the load tending to increase the'slip; (2) the magnetic pull tending to decrease the slip; (3) the frictional pull resulting from centrifugal and spring force, tending also to decrease the slip; and, when a storage battery is used, (4) the power of the battery tending, when the voltage generated by the armature is less than that of the battery, to increase the slip, by trying to drive the two rotors in opposite directions to cause the engine to speed up and the load to slow down, this action being like that which occurs in starting the engine.

I have found that a proper adjustment of the weight of the brushes and moving parts associated therewith, or a proper adjustment of the pressure of the springs, or a combination of both features, enables such a balance between these sets of opposing forces to be obtained that at a predetermined (fixed) rate of speed on an unobstructed roadway or any fixed rate of speed above the predetermined fixed rate of speed of the auno current is twenty miles an hour, the parts are so adjusted that at that speed, the frictional pull assists the magnetic pull between the two rotors to keep the slip at such an amount that the clutching current is generated at a voltage practicallv' the same as that of the battery. If new the speed of the au tomobile be increased for example from twenty to twenty-five miles per hour, the drag of the machine will momentarily during this increase of speed increase the slip between the rotors, thus causing additional.

current to be generated to flow into the battery. As soon as the twenty-five mile speed is reached and maintained the increased centrifugal pressure, due to the in creased speed, assisting the magnetic pull between the rotors, will again bring the slip'to practically the same as that when running twenty miles per hour and practically no current will be flowing through the batteries. When the speed of the automobile is diminished fromthis higher speed, there is a momentary tendency for the slip to diminish, which would then result in lowering the voltage at the brushes below that of the battery, and in consequence permit a flow of current from the battery; but this tendency is again corrected, because since the dynamo-electric clutch is shunt wound, the battery would immediately send current over the armature ina reverse direction and cause an opposing reaction between the rotors tending to again increase the slip and thus maintain the slip at the normal point with the battery still connected but with practically no current flowing through it.

In practice, it has been found that these actions and reactions so completely maintain the clutching action of the two rotors, that lei practically receiving no current'above the Ipredetermined sfpeed point, except during t e short time 0 increasing the speed, and there is no overchargingof the battery. It will be further apparent that this centrifugal action may be utilized to assist the magnetic clutching-effect be tween therotors of the dynamo-electric clutch, even in the absence of the battery from the system. These results are preferably obtained by'utilizing only those parts, such as the brushes and lever arms, already present in the dynamo-electric machine.

may, however, if desired, used a centrifugally-opcrated sliding clutch, entirely independent of the commutator, in which case any suitable form of commutator other than that shown, may be used. In this modified construction, a friction ring is secured to or formed as a part of one of the rotors and coiiperating centrifugally-operated sliding members are arranged to engage the inner surface of this friction ring. Such a construction is shown in Figs. 9 and 10 of the drawings, in which the dynamo-electric clutch is, for convenience of illustration, schematically shown. Referring to these Figs. 9 and 10, A is the engine shaft to which is secured the casing C, carrying the field magnets D. cured to the driven shaft B. J" is the commutator, secured to the armature and having the commutator bars L, on which bear the brushes Rf, R, carried by brush-holders secured to the drum 0'. S are springs for holding the brushes against the commutator.

o circuit connections are shown, as these will be readily understood from the revious more detailed description of the ynamoelectric clutch.

As shown in Fig. 9, the casin C is later ally extended, and, arranged to ear against the inner surface of the extended portion, are a series of weighted pressure blocks 32, adjustably and removably secured to arms 31, which, are pivoted to the ring 30, se-

the battery is cured to the shaft B. Springs 33 located between the heels of the aims 33 and the ring 30 normally prevent engagement of the blocks 32 with the casing, or the arms may be made of spring metal to normally hold the blocks away from the casing. while permitting them to engage, upon the development of sufiicient centrifugal force. When the shaft rotates at sufiicient speed, the weights are thrown outwardly by centrifugal force and rub with a sliding friction against the inner surface of the casing.

By using pressure blocks of proper weight, or ad usting the positions of the weights on the arms, the amount of friction developed by the rubbing of the pressure blocks against the inner surface of the casing can be regulated to the desired degree.

The armature F is se and arranged niecgcei Obviously, this system is also applicable when a storage battery is used, the operation then beingthe same as that above dew 7 the flexibihty of the the usual re ulating do urther advantage of my invention is I clutch, as compared with the rigidity of a mechanical clutch, diminishes the cost of operation in that the engine operates without jar or strain, especially in starting or changin speed, and at the same time and for a' li e reason, the wear of the tires is diminished. v

My invention permits the utilization of the whole power of the gas-enginethrough its whole range of speeds, in driving the load shaft, through gears or otherwise, except for the. loss of the small fraction of the whole ower lost in the clutch.

While 1 have shown the rotating field magnet connected to the gas-engine shaft, and the rotating armature to the driven shaft, this arrangement may be reversed.

This application is a division of my earlier application September 18, 1913.

I claim V l. A dynamo-electric clutch having revoluble field and armautre elements, one of said rotors having movably connected thereto parts adapted to be actuated by centrifugal force slidingly to engage said other rotor, said parts the centrifugally produced friction assists the magnetic clutching action and helps compensate any tendency to increased slip at high speed.

2. A shunt wound dynamo-electric clutch having revoluble field and armature elements, one of said rotors having movably connected thereto parts adapted to be actuated by centrifugal force slidinglyto en gage said other rotor, said parts eing so proportioned that the centrifugally produced friction assists the magnetic clutching action and helps, compensate any tendency to increased slip at high speed.

3. A dynamo-electric clutch having revoluble field and armature elements, one of said rotors having movably connected thereto Ipirts adapted to be actuated by centrifuga Serial No. 790,538, filed being so proportioned that orce slidingly to engage with said other men'ts, one of said rotors having movably connected thereto parts'adapted to be actuated by centrifugal force slidingl to engage said other rotor, said parts being so proportioned that the centrifugally pro duced friction assists the magnetic clutching action and helps compensate any tendency to increased slip at high speed, and adjustable means for regulating the friction between said parts and member.

5. A dynamo-electric clutch hav'inga revoluble field magnet and a revoluble armature, a commutator ring carried by said and having an internal bearing surface,

. brushes movably secured to said field magnet and bearing outwardly on the internal surface of the commutator, springs for pressing said brushes outwardly against the internal bearing surface of the commutator and means for adjusting the pressure of said springs, the weight of the brushes and the pressure of the springs being so adjusted that the combined pressure due to effect of the centrifugal and spring action Will assist to the desired extent the magnetic clutching action.

.A dynamo-electric clutch having a revoluble field magnet and a revoluble armature, a commutator carried by said armature and having an internal bearing surface.

brushes movably secured to said field mag net and bearing outwardly on the internal surface of the commutator, spring pressed arms for holding said brushes outwardly against the internal bearing surface of the commutator, and means for adjusting the spring pressure, the Weight of the brushes andarrns and the pressure of the springs being so adjusted that the combined pressure due to efiect of the centrifugal and spring action will assist to the desired extent the magnetic clutching action.

9. Adynamo-electric clutch having revoluble field and armature elements, a storage battery having its respective poles connected to like poles of the armature, one of saidrotors having movably connected thereto parts adapted to be actuated by centrifugal force, slidingly to engage said other rotor, said parts being so proportioned that he centrifugally produced friction assists the magnetic clutching action and helps "compensate-any tendency to increased slip at high speed.

9. A shunt Wound dynamo-electric clutch having revoluble field and armature ele-- ments, a storage battery having its respective poles connected to like poles of the armature, one of said rotors having movably con-nected thereto parts adapted to be actuated by centrifugal force slidingly to engage said other rotor, 'said parts being so proportioned that the centrifugally produc'e'd friction assists the magnetic clutching'ac'tion and helps compensate any tendency to increased slip at high speed.

1 0. A dynamo-electric clutch having revoluble field and ar 'naiture elements, a stora-gebattery having its respective poles connected to like poles of the armature, one of rotors having movably connected thereto parts adapted to be actuated by centrifugal force slidingly to engage with said other rotor, said parts being so proportioned that the centrifugally produced friction assists the magnetic clutching action and helps compensate any tendency to increased slip athigh speed, and adjustable means for regulating the friction between said parts and member.

11. A shunt Wound dynamo-electric clutch having revoluble field and armature ele- 9E merits, a storage battery having its re: spective poles connected to like poles of the armature, one of said rotors having movably connected thereto parts adapted to be actuated by centrifugal force slidingly too to engage said other rotor, said parts being so proportioned that the centrifugally produced friction assists the magnetic clutching action and helps compensate any tendency to increased slip at high speed; and adjustable means for regulating the friction between said parts and member.

12. QA dynamo-electric clutch having a. revoluble field magnet and a revoluble arma ture, a storage battery having its respective 11o poles connected to like poles of the arma.- ture, a commutator ring carried by said armature and having an internal bearing surface, spring pressed current collecting devices carried by said field-magnet bearing outwardly on the internal surface of the commutator, the Weights of said devices and the spring pressure being so adjusted that the combined pressure due to the effect of the centrifugal and spring action will assist to the desired extent the magnetic clutching action.

13. A dynamo-electric clutch having a revoluble field magnet and a revoluble armature, a storage battery having its respective poles connected to like poles of the armature, a commutator carried by said-armature and having an internal bearing surface, brushes movably secured to said field magnet and bearing outwardly on the in- 1m Y mem le ti1re,--: a commutator-earned by said erme- .Witnewes:

ternal surface of.;the= oommutatog, -sp ripgs net and, bearing outwardly on the internal for pressin' said brushes outwerflgy t surface of the" commutator, spring pressed "the mterna bearingfsulzface ofithe-eommu- "-.m-m s for. holding said brushes outwardly tutor and meuris-for ad ustmg the psessur'e ugemst. the internal bearing surface of the 5' of said springs, the welght of the commutator; and means for adjusting the e and the pressure of the spnngs hel ng so sprung pressure; the weight of the brushes adjusted thatthe eombmed ressure due to zm d arms end, the 'ressur'e of the s rings 'efiect of the centrifugal'an sprmg actlon bemgso adjusted t at the eombiue pres- 25 will assist to the desired extent the magnetic sure due to ,eflect of the centrifugal and 10' clutching-action. .4 1 sprm ectlon W111 assist to the desn'ed ex-' 14. A dvnamo-electricfcluteh ,hevmg a tent t e mugnetie clutehin action. revolublefield magnet and revpluble erma- Intestimonv whereof I u ix my signature ture, a storage battefii hevmgilts respective m presence of two witnesses. poles oonnecte'd to exgoles of the arms WILLIAM MGRRILSON.

ture endhtwih an internal heerin' surface, WARD S. Penny, brushes moveb y secured'to smd eld megl L. W. Gowns. 

